Triethylamine → (S)-tert-Butyl 4-((R)-2-(((tert-butyldimethylsilyl)oxy)methyl)-5-((methylsulfonyl)oxy)pentyl)-2,2-dimethyloxazolidine-3-carboxylate

Participants

Reaction Steps

To a solution of (S)-tert-butyl 4-((R)-2-((tert-butyldimethylsilyloxy)methyl)-5-hydroxypentyl)-2,2-dimethyloxazolidine-3-carboxylate (32 g, 74.2 mmol) and Et3N (22.5 g, 226 mmol) in CH2Cl2 (400 mL) was added a solution of MsCl (10.1 g, 89 mmol) in CH2Cl2 (50 mL) at 0-5° C. After addition, the reaction mixture was allowed to warm to rt and stir for 1 hr. The reaction was washed with water (200 mL) and the aqueous layer was extracted with CH2Cl2 (3×150 mL). The combined organic layers was washed with 10% citric acid (60 mL), sat. NaHCO3 (60 mL) and brine (100 mL), then dried over Na2SO4, filtered and concentrated to give (S)-tert-butyl 4-((R)-2-((tert-butyldimethylsilyloxy)methyl)-5-(methylsulfonyloxy)pentyl)-2,2-dimethyloxazolidine-3-carboxylate (37.7 g, 100%), which was used in the next step without purification.

Provenance & Evidence